Joint replacement surgery is quite common and it enables many individuals to function properly when they otherwise would not be possible to do so. Such patients of joint replacement surgery typically suffer from osteoarthritis or rheumatoid arthritis. Artificial joints usually comprise metallic, ceramic and/or plastic components that are fixed to existing bone.
Such joint replacement surgery is otherwise known as total joint arthroplasty. Total joint arthroplasty is a well-known surgical procedure by which a diseased and/or damaged joint is replaced with a prosthetic joint. In a typical total joint arthroplasty, the ends or distal portions of the bone adjacent the joint are resected or a portion of the distal part of the bone is removed and the artificial joint is secured thereto.
A hip prosthesis may be modular or consist of more than one component. Such modularity has many advantages including reduced inventory, greater selection of an optimum hip prosthesis, and to assist in performing less invasive surgical procedures with smaller skin incisions and less soft tissue disruption.
One such modular hip system includes a sleeve that is slideably fitted over distal stem for insertion into the femoral canal of a femur. Such a sleeve type modular system is sold by DePuy Orthopedics Inc., Warsaw, Ind., as the S-ROM hip system. The S-ROM hip system includes a distal stem, a sleeve which slideably fits over the distal stem, and a neck trial that fits to the distal stem. The modular implant of the S-ROM hip system includes a stem to which a sleeve may slideably fit.
During the S-ROM surgical procedure, a sleeve is positioned proximally in the reamed canal of a resected femur. Once the sleeve, in the form of a trial sleeve, is positioned into the canal at the resected surface of the femur, a distal stem trial is positioned in the canal through the sleeve until it is seated into its proper position. At that point, a neck trial is secured to the distal stem trial making the trial stem assembly. A trial head is placed on the trial neck and a trial reduction is performed. If the trial reduction is satisfactory, the trial assembly is removed from the canal of the femur and an implant sleeve is positioned in the canal and an implant stem is inserted through the opening of this sleeve into position.
During the S-Rom surgical procedure, the level of the horizontal neck cut and the placement of the sleeve are the main contributors to the leg length of the stem. The surgeon first makes the initial resection. If the initial horizontal neck resection is too high, of if the sleeve is positioned distally into the stem to obtain the optimum leg length, the surgeon is required to remove excess bone that is superior to the top edge of the trial sleeve. Removing this excess bone reduces the risk of bony impingement.
The current method for removing this excess bone is in the form of using an osteotome or a saw to remove the bone, orienting the saw or the osteotome along the top surface of the sleeve trial. The top surface of the sleeve trial may be scraped or defaced to the point that metal shavings are released into the patient and the size etchings on the sleeve trials may become illegible.
The present invention is directed to alleviate at least some of the aforementioned problems with the prior art.